Spacecraft are exposed to a wide range of radiation environments during service. The external surfaces of the spacecraft may be heated by absorption of radiation (e.g., solar radiation) and/or cooled by infrared radiation. The heating and cooling may occur alternately as the spacecraft in and out of a line-of-sight of the sun. The heating and cooling may also occur simultaneously when a side facing the sun is heated while a side facing the void of space is cooled. The temperature of the spacecraft is based on the balance of heating and cooling in the spacecraft.
Prior art materials have static emissivity properties that are inherent to the materials and cannot be changed. As a result, obtaining a material that has a desired emissivity in a particular radiation frequency range involves finding a suitable material having the desired emissivity property.
Accordingly, there is a need for an apparatus having a tunable emissivity. The apparatus may be incorporated into a surface. Tuning may involve increasing, decreasing, and/or optimizing an amount of radiated energy reflected, absorbed, and/or emitted.